Locking device



I May 26, 1936 B. s. BERNHARD LOCKING DEVICE Filed Sept. 27, 1954 Patented May 26, 1936 UNITED STATES PATENT OFFIQE 1 Claim.

One object of my invention is to provide a simple and inexpensive locking device which may be used without a lock washer.

Another object is to provide such a device which is capable of locking itself against loosening and is also capable of holding two slidably connected parts immovable with relation to each other.

A feature of my invention is a screw, nut, bolt or similar device provided with a threaded portion and having a projection extending axially of the device in the direction in which the device moves when being applied, said projection being radially outside of said threading and in the preferred form the device has a head which is undercut.

Other features will be pointed out below.

In the drawing Figure 1 is an end view of a screw embodying my invention;

Figure 2 is an elevation, partly in section, of the screw of Figure 1;

Figure 3 is an end elevation of the other end of the screw of Figures 1 and 2;

Figures 4 and 5 are elevations of modifications described below;

Figures 6 and 7 are elevations of nuts described below;

Figure 8 is a partial plan showing my locking screw holding a square rod and square tube in fixed relative position;

Figure 9 is an elevation, partly in section on line 99 of Figure 8, of the parts of Figure 8; and

Figures 10 and 11 are similar to Figures 8 and 9 respectively but showing a modification described below, Figure 11 being partly in section on line lI-II of Figure 10.

In the form of Figures 1 to 3 I show a screw which is threaded at I and has in its head 2 a hexagonal socket 3 to receive a suitable tool for turning the screw to tighten it. The head has a projection 4 which extends exially of the screw in the direction in which the screw moves when it is applied, this projection lying radially outside of the threading so that it may engage the desired cooperating element, such as III or I5, or I9, described below. This projection is annular or circular, and, adjacent to it, the head is undercut at 5, the projection being formed to provide a continuous or endless cutting edge which is capable of locking, or of sealing, or of locking and sealing, as desired.

In Figure 4 the screw is similar to that shown in Figures 1 to 3 but the head 2 is hexagonal and locks the socket of Figure 2.

In Figure 5 the screw is provided with an annular serrated projection 6, the serrations being reversed with relation to the lead of the thread- In Figure 6 I show a hexagonal nut I having an annular serrated projection I like the serrated projection Ii of Figure 5.

In Figure '7 I show a hexagonal nut 8 having an annular projection 8 like the projection 4 of Figure 2.

This locking unit or device I have found particularly useful in connection with slidably connecting parts and for locking such parts against relative movement. This combination of parts is particularly illustrated in Figures 8 to 11, inelusive.

In Figures 8 and 9 I show a square rod 9 which fits slidably within a square tube II], the latter having a slot II so that the threaded portion I of the screw may pass through the slot, the projection 4 engaging tube III at parts Ill and l to hold the rod and tube in the desired fixed relative position, the slot permitting desired adjustment.

In the form of Figures 10 and 11 the threaded portion I of the screw of Figure 4 is shown engaging flat bar I 2 while part of the threaded portion passes through slot IS in flat bar I4, the annular projection 4 engaging portions I4 and I4 of bar I4 similar to the engagement in Figure 8.

Slidably connected parts, such as I have illustrated in connection with the locking stud and gripping head thereon, are used in many fields, and I have employed the same effectively in order to provide adjustment for one of the hinged arms of a door closer. As will be noted, the head on the stud, which may be either a nut as shown in Figures 6 and 7 or an integral head as shown in Figures 2, 4 and 5, spans the slot so that when the undersurface of the head engages the surface of the slotted part or bar, the surface is effectively gripped and the bar held against movem'ent relative to the other bar or part of the joint. By providing a continuous or endless wedge-form projection on the undersurface of the head, it is not necessary to determine the final position of the head when the parts are clamped, since regardless of the position of the head the gripping projection will engage and cut into the surface of the slotted bar at the sides of the slot. Moreover, the circular form of the projection serves to provide scores or grooves in the surface of the bar at the sides of the slot which are directed at an angle to the longitudinal line or length of the slot, thereby effectively resisting any tendency of the bars to move relative to one another.

It will be clear that while I have shown several embodiments of my invention as examples, yetmy invention is applicable to a wide variety of USES.

It will be noted that the screw is provided with a relatively sharp endless or circular cutting edge on the under side of the head. In the case of a nut, this same cutting edge is provided on the under side. This edge may be of any suitable form or at any suitable angle, and extends only slightly beyond the surface of the head :of the screw or of the nut, so that it may readily cut into the surface against which it makes contact in order to permit the flatgpartof 'the'screwor nut to make contact with that surface and to assist in effecting a tight joint. When the screw or-nut is tightened, this-edge cuts its .way into the surface with which it:makes contact, spreading the metal and creating a distinct .binding effect due to the tendency of the material of the surface to close-in about the cutting edge. This holds the screw or-nut tightly to resist turning in the loosening direction. -When combined with a longitudinally slotted member, as shown in Figures 8 to 11,inclusive, the continuous projection will, in any clamping position of the device,'grip and score .or cut the surfaces at the sides .of the slot. The cutsiformed are curvilinear and along linesat angles to the length of .the slot or bar, thus efl'ectively resistinglongitudinal movement of the bar in the direction of the length of the slot.

The under side of the head of the screw or nut can be under cut deeper or the head of the screw may be made thinner. With this construction the head of the screw or the nut would tend to assume a concave form when tightened down, giving a spring effect and tending to keep the cutting edge in close contact with the material against whichit is tightened. The .cutting edge should be continuous.

What I claim is:

In combination with a pair of slidably connected parts, one of which has a slot elongated longitudinally thereof, a clamping device comprising a'threaded slot mounted in the other of said parts and extending through the slot in the first'mentioned part, and a head on said stud of .sufficient width to span said slot whereby its unthesides'of the slot by displacement of the matcrial of said surface in a radial direction whereby to form at the sides of the slot curvilinear scores angularly disposed with reference to the sidesof the slot.

BENJAMIN S. BERNHARD. 

